This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. During and after surgery it is a standard procedure to administer intravenous fluid therapy to replace blood and fluid losses. Fluids normally given are saline-based solutions. These solutions distribute into the blood and tissues of the body. We suggest that certain medicines (beta-adrenergic agents) affect the distribution of intravenous fluid therapy. The specific aims of this project are to find out what makes fluid to move out from the blood into the tissues and how medicines (beta-adrenergic agents) may affect this. We propose to test, in people, the affect of giving intravenous fluid given over a short period of time. We want to know how much of the fluid stays in the blood and how much fluid goes into the tissues. In order to do this study, a series of blood samples and measurements are needed from the leg. One part of this study is to study how fluids distribute in a normal state. Another part of this study is to see if distribution of fluid changes when patients are given medications called beta-blockers. We will measure vital signs throughout the study period for safety and for scientific reasons. We will enroll 48 healthy people between the ages of 18 and 50 years. The importance of these studies will give doctors 1) a better understanding of fluid therapy 2) information about how certain medicines impact fluid therapy 3) a better fluid therapy plan that may decrease illness and death.